Engine fuel supply



Jan. 10, 1967 B. WALKER ENGINE FUEL SUPPLY Filed March 24, 1964 -mmm United States Patent O 3,297,103 ENGINE FUEL SUPPLY Brooks Walker, 1280 Columbus Ave., San Francisco, Calif. 94133 Filed Mar.I 24, 1964, Ser. No. 354,232 3 Claims. (Cl. 180-77) This invention pertains to improvements in the control of fuel shut off during closed throttle accelerations at engine speeds which is desirable for reductions in unburned hydrocarbons emitted from the exhaust particularly during decelerations.

Much work has been done and many patents issued on control for idle fuel but rnost have operated on the suction that is higher than when idling while decelerating or on an engine driven governor with other controls to turn the idle fuel on at lower engine speeds to prevent stalling.

This invention employs a governor driven not from the engine but from the vehicle drive shaft so that the idle fuel is not shut off when decelerating the engine r.p.m. while idling. If the idle fuel is kept on during acceleration, deceleration and higher idle speeds, it is less liable to stall, particularly when starting cold and warming up.

Another feature is a very simple wiring diagram that controls the idle fuel to keep it on at all times except when decelerating above a predetermined vehicle speed.

Other features will be a single switch that can turn off the idle fuel and the ignition for deceleration while descending a long or steep grade with a reduction in wasted fuel, reduced unburned hydrocarbons, and reduced danger to muffler or exhaust pipe backfire. Other feature of this invention will be more particularly pointed out in the accompanying specifications and claims.

I have illustrated my invention in the accompanying drawing, in which:

FIG. l is a side elevation of an engine and control circuit partly in section and partly diagrammatic sh-owing one form of the invention.

FIG. 2 is a chart of the function of the device during various operating cycles.

In FIG. 1 I have shown an engine 10, a clutch or automatic transmission that can disconnect the rotating parts of the engine from the drive shaft 55 rotating in housing 9. A carburetor 8 with a venturi section 12 is located in the center barrel section of the carburetor. There is a throttle butterfly 13 shown closed. There is also a choke 1li on the intake side of venturi 12. There is lan idle fuel and air port 18 closed by valve 19 urged to closed position by spring 21 acting on shoulder 20. Solenoid 22 actuates valve 19 to the open position when energized. Screw and lock nut 23 limit the opening motion to effect a control or adjustment of the idle fuel.

Idle fuel flows from the float bowl passing through port 18 below closed butterfly 13, through pick up tube 15, down tube 16, past transfer port 17, to idle port 18, as controlled by valve 19. Additional idle air enters through tube 24, is controlled by valve 25, and enters below throttle butterfly 13 at orifice 26 to make the air from tube 24 spin around the carburetor barrel below the butterily valve 13 for better mixing with the rich fuel and air entering through idle fuel port 18. A bleed or main jet 27 is connected by passage 28 to fuel pick up tube 15.

A governor 50 is driven by pulley 54 on drive shaft 55, ibelt 53, and pulley 52. An operating stem 51 has insulated end 52a and operates to open switch 41 above a predetermined drive shaft speed.

In operation, battery 30 is connected to switch 32 operated by key 29, line 33 to the ignition system 35 by line 34. Line 36 connects to throttle switch 37 which is operated `by throttle arm 38 to open switch 37 when the throttle is closed, as shown. Switch 37 will be closed 3,297,1@3 Patented dan. 10, 1967 when the throttle is in all operating positions except idle or closed position. Arm 38 has insulated end 38a for contacting switch 37. Lines 39 and lill connect to switch 41 which, as stated, is open when the drive shaft is operating above a predetermined speed.

The chart of FIG. 2 shows the operation of throttle switch 37 `and governor switch 41 in many operating conditions.

One of the main features of this invention is a circuit that keeps the idle fuel on while the engine is decelerating in r.p.m. from a high idle speed while the vehicle is not moving, `as in cold warm up, etc. If the idle fuel is turned off while decelerating from 3000 to 1000l rpm. while idling cold, it will have more tendency to stall than if the idle fuel is left on for these short decelerations while idling.

I have illustrated my invention in these various forms; however, many other variations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and description herein are purely illustrative and are not intended to be in any sense limiting.

I claim as my invention:

1. A prime mover including in combination an engine having a carburetor, a throttle valve for said carburetor, a drive shaft, a clutch for connecting and disconnecting said drive shaft to said engine, 'an idle fuel system for supplying idle fuel to said engine while idling, a device for shutting off the flow of said idle fuel to the engine, a speed sensitive actuator for said device connected to be driven by said drive shaft, control means actuated by closure of said throttle valve, and means controlled by said speed sensitive actuator and said control means operable to actuate said device and turn otf said idle fuel in a first condition when said drive shaft and engine are decelerating from high -speed with closed throttle, and to leave on said idle fuel in .a second condition while said engine is decelerating from high speed. and said drive shaft is stationary, said device including an electrical circuit `and two switches in parallel, a rst one of said switches being operated by said speed sensitive actuator and the second of said switches being operated in conjunction with the operation of said throttle valve.

2. A prime mover including in combination an engine having a carburetor, a throttle valve for said carburetor, a drive shaft, .a clutch for connecting and disconnecting said drive shaft to said engine, an idle fuel system for supplying idle fuel to said engine while idling, a normally energized electrically operated device for controlling the flow of said idle fuel to the engine and cutting off rsaid flow when deenergized, a governor driven by said drive shaft, a first normally closed electrical switch in series with said device and opened by said governor at high drive shaft speeds, and a second normally closed switch in series with said device `and in parallel with said first switch and opened by closure of said throttle valve, said device being deenergized by said switches to turn off -said idle fuel in a first condition when said drive shaft and engine are decelerating from high speed with closed throttle, and to leave on said idle fuel in a second. condition while said engine is decelerating from high speed and said drive shaft is stationary.

3. In an automotive vehicle comprising an internal combustion engine, a drive shaft for driving said vehicle, and means for connecting and disconnecting the drive shaft to and from the engine, said engine having `a carburetor and throttle valve therefor; yan idle fuel system for supplying fuel to said engine, and means for shutting olf and turning on the How of fuel through said idle system, said latter :means comprising a speed responsive device connected to the drive shaft for turning on the low of idle fuel when the drive shaft rotates below a preselected speed and means indepedent of said speed responsive device connected to the throttle for turning off the flow of idle fuel when the throttle is closed and the drive shaft rotates above said preselected `speed whereby on deceleration of the engine with the drive shaft stationary and the throttle closed fuel will ow through the idle system, While on deceleration of the drive shaft and engine to the preselected speed with the throttle closed there is no flow of idle fuel.

Cil

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 6/1932 France.

A. HARRY LEVY, Primary Examiner. 

3. IN AN AUTOMOTIVE VEHICLE COMPRISING AN INTERNAL COMBUSTION ENGINE, A DRIVE SHAFT FOR DRIVING SAID VEHICLE, AND MEANS FOR CONNECTING AND DISCONNECTING THE DRIVE SHAFT TO AND FROM THE ENGINE, SAID ENGINE HAVING A CARBURETOR AND THROTTLE VALVE THEREFOR; AN IDLE FUEL SYSTEM FOR SUPPLYING FUEL TO SAID ENGINE, AND MEANS FOR SHUTTING OFF AND TURNING ON THE FLOW OF FUEL THROUGH SAID IDLE SYSTEM, SAID LATTER MEANS COMPRISING A SPEED RESPONSIVE DEVICE CONNECTED TO THE DRIVE SHAFT FOR TURNING ON THE FLOW OF IDLE FUEL WHEN THE DRIVE SHAFT ROTATES BELOW A PRESELECTED SPEED AND MEANS INDEPENDENT OF SAID SPEED RESPONSIVE DEVICE CONNECTED TO THE THROTTLE FOR TURNING OFF THE FLOW OF IDLE FUEL WHEN THE THROTTLE IS CLOSED AND THE DRIVE SHAFT ROTATES ABOVE SAID PRESELECTED SPEED WHEREBY ON DECELARATION OF THE ENGINE WITH THE DRIVE SHAFT STATIONARY AND THE THROTTLE CLOSED FUEL WILL FLOW THROUGHT THE IDLE SYSTEM, WHILE ON DECELERATION OF THE DRIVE SHAFT AND ENGINE TO THE PRESELECTED SPEED WITH THE THROTTLE CLOSED THERE IS NO FLOW OF IDLE FUEL. 